Alternative Names

Endocarditis - infectious

Causes

Endocarditis is usually a result of a blood infection. Bacteria or other infectious substance can enter the bloodstream during certain medical procedures, including dental procedures, and travel to the heart, where it can settle on damaged heart valves. The bacteria can grow and may form infected clots that break off and travel to the brain, lungs, kidneys, or spleen.

Most people who develop infectious endocarditis have underlying heart disease or valve problems.

However, an organism commonly found in the mouth, Streptococcus viridans, is responsible for about 50% of all bacterial endocarditis cases. This is why dental procedures increase your chances for developing this condition. Such procedures are especially risky for children with congenital heart conditions. As a result, it is common practice for children with some forms of congenital heart disease and adults with certain heart-valve conditions to take antibiotics before any dental work.

Other common culprits include Staphylococcus aureus and enterococcus. Staphylococcus aureus can infect normal heart valves, and is the most common cause of infectious endocarditis in intravenous drug users.

Less common causes of infectious endocarditis include pseudomonas, serratia, and candida.

Treatment

You will be admitted to the hospital so you can receive antibiotics through a vein. Long-term, high-dose antibiotic treatment is needed to get rid of the bacteria. Treatment is usually given for 4 - 6 weeks, depending on the specific type of bacteria. Blood tests will help your doctor choose the best antibiotic.

Surgery may be needed to replace damaged heart valves.

Outlook (Prognosis)

Early treatment of bacterial endocarditis generally has a good outcome. Heart valves may be damaged if diagnosis and treatment are delayed.

Possible Complications

Blood clots or emboli that travel to brain, kidneys, lungs, or abdomen

Antibiotics are more likely to be recommended those with the following risk factors:

Artificial heart valves

Certain congenital heart defects, both before or possibly after repair

History of infective endocarditis

Valve problems after a heart transplant

Continued medical follow-up is recommended for people with a previous history of infectious endocarditis.

Persons who use intravenous drugs should seek treatment for addiction. If this is not possible, use a new needle for each injection, avoid sharing any injection-related paraphernalia, and use alcohol pads before injecting to reduce risk.

Wilson W, Taubert KA, Gewitz M, et al. Prevention of infective endocarditis: guidelines from the American Heart Association: a guideline from the American Heart Association Rheumatic Fever, Endocarditis, and Kawasaki Disease Committee, Council on Cardiovascular Disease in the Young, and the Council on Clinical Cardiology, Council on Cardiovascular Surgery and Anesthesia, and the Quality of Care and Outcomes Research Interdisciplinary Working Group. Circulation. 2007 Oct 9;116(15):1736-54.